Worn like a pair of pants and meant to fit underneath a soldier’s regular gear, the suit is made of soft, functional textiles, and mimics the action of leg muscles and tendons.

The suit was tested over a three-mile cross-country course, which consists of paved road and two miles of semi-rugged terrain. According to Boynton, the suit’s been in development for about three years. In October, it will be tested on a six-mile course.

“It’s like a rubber band,” said one soldier, who noted he wasn’t sure how well the suit would boost performance. However, medically, the apparatus may help prevent muscle tears, and other injuries that stem from carrying heavy loads over long distances.

Steve Jurvetson had a video and picture of the latest DARPA Warrior Web exosuits from Harvard and SRI at a Feb, 2015 meeting.

The Harvard team uses linear actuators on the side of the backpack (instead of twisting filaments with the SRI team) to get a 10% net improvement in walking with load. The backpack is just a weight load; all of the actuators and batteries are in the black box.